made the pack completely portable and wrote relevent bat files to go with it

gitportable/mingw64/share/doc/git-doc/RelNotes/2.0.3.adoc

@@ -0,0 +1,17 @@
+Git v2.0.3 Release Notes
+========================
+
+ * An ancient rewrite passed a wrong pointer to a curl library
+   function in a rarely used code path.
+
+ * "filter-branch" left an empty single-parent commit that results when
+   all parents of a merge commit gets mapped to the same commit, even
+   under "--prune-empty".
+
+ * "log --show-signature" incorrectly decided the color to paint a
+   mergetag that was and was not correctly validated.
+
+ * "log --show-signature" did not pay attention to "--graph" option.
+
+Also a lot of fixes to the tests and some updates to the docs are
+included.